Male/Female Trade-Off in Hermaphroditic Y-Chromosome Deletion Mutants of the Dioecious Plant <i>Silene latifolia</i>

The evolution of dioecy from hermaphroditism allows for avoidance self-pollination, and its evolutionary background has been investigated both experimentally theoretically since it was first proposed by Darwin. To reproduce this evolution, we screened hermaphroditic mutants Silene latifolia using heavy-ion beam or γ-ray irradiation characterized the phenotypes their floral organs. Our scatterplots indicate severe deviations trade-off relationships between pollen ovule numbers seed germinated in mutant S. latifolia. These presumably led to promotion ancestral state infer likely flower phenotypic characteristics plant before evolving dioecy, flowers viscosa, a naturally related were also characterized. viscosa exhibits spatial separation stamens pistils within (reverse herkogamy) temporal stamen pistil maturation (dichogamy), raising question whether latifolia, which is thought be state, would possess these functions. We show that two dioecious exhibit signs protogyny dichogamy) approach herkogamy, as constantly longer than stamens. findings illustrate self-pollination mechanism balance investments into male female